#!/usr/bin/env Python
# coding=utf-8

class Calculator(object):
    is_raise = True

    def calc(self, express):
        try:
            return eval(express)
        except ZeroDivisionError:
            if self.is_raise:
                print("zero can not be division.")
            else:
                raise


if __name__ == "__main__":
    c = Calculator()
    # c.is_raise=False
    print(c.calc("8/0"))
